For ha’agalas keilim during the year do you need to use a pareve pot, or can it be done in any pot?
To kasher counters for pesach with a kumkum, does the kumkum need to be kosher for pesach?
You can use any pot you want, however the pot and the utensils being kashered should not have been used within the last 24 hours. The reason is since the pot and utensils are not a ben yomo, the absorbed taste that comes out can not prohibit anything.
When kashering counters with a kumkum it is permitted to use the “chometz” kumkum for pouring the hot water over the counters
Kovetz Halchos (Pesach) 11 end of ftnt. 5.